Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
12-27-2011, 07:25 AM   #1
Forum Member

Join Date: Dec 2011
Location: Arkansas
Posts: 96
645d freezes when writing to card

New 645D, new formatted Sanddisk 32gb card (I've tried two different cards), temp about 30 degrees F. Sometimes when I make exposures longer than a couple of seconds, the camera will hang when writing the file to disk. The "instant review" image and histogram shows up at the correct time, and the red light that shows the file is being written to the memory card lights up, but then the review image screen goes back to normal and the red light continues to be lit - it never completes writing the file to the card - ever. I can continue to use all functions of the camera, including take more pictures, and they expose correctly, but the red light never goes out and no file is ever written to the card (no matter how many pictures are taken, none are written to the card). Even if I turn the camera off the red light remains lit and never goes off or never completes writing the original picture to the card. The only way to reset this is to remove the battery and reinsert, then everything is back to normal and I can take and record pictures again. Nothing got written to the card once the red light remained lit though. Everything seems to work fine with shorter exposures.

Has anyone seen this before and have an idea what is going on? Could I have two bad new cards and they just don't like long exposures in cool weather?

Any thoughts would be most appreciated - thanks!

12-27-2011, 07:32 AM   #2
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 51,519
If you have a different type of card I would test the camera with that and see if you can reproduce the problem.

Also, you should ensure that the:
-camera firmware is at the latest version
-card is formatted in the camera, not on your desktop
-card is not write-protected via the lock button
12-27-2011, 07:49 AM   #3
Forum Member

Join Date: Dec 2011
Location: Arkansas
Posts: 96
Original Poster
Thanks Adam. Yes to all of the above - it works normally most of the time, but seems to lock up when shooting long exposures in cool weather.
12-27-2011, 10:28 AM   #4
Senior Member

Join Date: Jun 2010
Location: Hamburg
Posts: 267
I have two SanDisk Extreme (16/8) at 30MB/s in my 645D (latest firmware) with no problem at all.
You do know that the 645D locks up completely when you have done (very) long exposures? After exposure the LCD screen counts down the time you have exposed - my guess is this is for processing the image. During this procedure you can't do anything with the cam.

First time I recognized the lock-up after a long exposure, I thought it was an error.

12-27-2011, 01:12 PM   #5
Forum Member

Join Date: Dec 2011
Location: Arkansas
Posts: 96
Original Poster
Are you talking about the dark slide exposure? That is not a lockup, and is normal when doing any exposure of a second or longer with most digital cameras. This equals the amount of the exposure (ten seconds for a ten-second exposure, etc.), and is normal on nearly all cameras (it takes an equal exposure with the shutter closed to map out hot pixels and subtracts them from the original data before writing to the card). That is not what is going on with my camera - the file fails to write to the card - it would run for two hours and never complete the task - and I can in fact use all the camera controls while this is going on, including taking pictures, none of them ever get written to the card. This is an obvious error either with the camera or the cards. Since it has only happened when the temp is in the 30s I doubt it is a Sanddisk card error - that would be really weird. On the other hand certainly the camera can handle cool temps. I'll keep messing with it and see if some other pattern develops, in the meantime if anyone else has had this issue please let me know. Thanks!
12-27-2011, 09:04 PM   #6
Forum Member

Join Date: Dec 2011
Location: Arkansas
Posts: 96
Original Poster
I just realized that the long-exposure noise reduction (dark frame exposure) only kicks in after a longer than 30 second exposure (normally kicks in at one second or longer for most other cameras) - so only when using bulb - so the issue I'm having is not related to this since it locks up while writing to the memory card at much shorter exposures. It seems to only happen below about 40 degrees F. It has worked OK when using Brand X memory cards tonight at 32 degrees, when the Sandisk cards failed, so it may be the Sandisk cards. Very odd behavior for a memory card to be temperature-dependant. I hope I can return them if that turns out to be the issue - and I do hope that is the issue since this camera certainly can work OK at below-freezing temps...

update - I left the camera outside all night to keep it cold and it is working normally this morning at 27 degrees with the Brand X card.

Last edited by jwoodland; 12-28-2011 at 04:39 AM.

  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
645d, camera, card, cards, exposures, file, image, light, medium format, pictures
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
645D SDHC Card Issue CDW Pentax Medium Format 3 06-17-2011 08:08 AM
SD card for 645d Fontan Pentax Medium Format 25 04-23-2011 09:47 AM
645D - SD card recipe ? VoltMan Pentax Medium Format 5 01-17-2011 03:50 PM
K-x freezes lescatalpas Pentax DSLR Discussion 8 06-18-2010 07:33 PM
K7 issues writing to memory card notion Pentax DSLR Discussion 6 08-06-2009 10:41 AM

All times are GMT -7. The time now is 05:49 PM. | See also:, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]